1. Field of the Invention
The present invention relates to a zoom lens adapted for use in a compact camera.
2. Related Background Art
Zoom lenses are recently employed even in compact cameras with lens shutters, and the zoom lens adapted for such use is disclosed for example in the U.S. Pat. No. 4,720,179.
However the zoom lens disclosed in said patent has as many as eight components and is difficult to supply inexpensively to the users.
For this reason, zoom lenses with fewer components are disclosed for example in the Japanese Laid-open Patents Sho 62-56917 and Sho 62-284319, and the U.S. Pat. Nos. 4,772,106 and 4,682,860.
Among these, the Japanese Laid-open Patent Sho 62-56917 proposes the use of an aspherical lens while the Japanese Laid-open Patent Sho 62-284319 proposes the use of a gradient-index lens, but the use of such elements is undesirable because such elements are more expensive than the ordinary spherical lenses.
Also, the U.S. Pat. Nos. 4,772,106 and 4,682,860 provide zoom lenses with 5 to 7 elements, but the zoom ratio of these zoom lenses is limited to 1.5 times.